<<<Calendar days between attainment of new high and eventual market peak Gain between attainment of new high and bull market’s endBest case 2,711 221.6%Worst case 132 2.3%Median of all 13 cases since 1954 417 18.4%Mean of all 13 cases since 1954 644 40.3%

On average following those 13 cases, according to Ned Davis’s firm, the bull market continued for another 644 days — nearly two years — and, in the process, gained an additional 40.3%.

The accompanying table reflects what they found upon focusing on the 13 instances since the S&P 500 was inaugurated in the 1950s in which, following a bear market, it reached a new high. >>

I don't know how they arrived at those criteria . But it does seem to indicate that you don't have to be in a hurry to leave what has been a bull market so far.